Js file of cutr.ml :)

script.js

  var zp = document.getElementById("r2");
zp.addEventListener('click', Lunc);
var zo = document.getElementById("expa");
zo.addEventListener('click', unc);

function unc(){
var x = document.getElementById("r1");
  if (x.style.display === "none") {
    x.style.display = "block";
  } else {
    x.style.display = "none";
  }
}
function Lunc(){
    var x = document.getElementById("r").required;
      var y = document.getElementById("r1");
    var url = x.value
    var alias = y.value

    // var al = alias.slice(8);

  var long = `https://cutr.ml/api/short?url=${url}&alias=${alias}`

     var tag = document.createElement("input");
  tag.setAttribute('readonly', true)
  tag.setAttribute('id', "tagg")
var xhttp = new XMLHttpRequest();

xhttp.open("GET",long);
     xhttp.onreadystatechange =  function() {
    // if(xhttp.readyState == 4) {
     //   if(xhttp.status == 200) {
            result = xhttp.responseText;
            js = JSON.parse(result)
            if (js['err']){
              tag.setAttribute('value', `Error: ${js['err']}`)
              return;
            }

        tag.setAttribute('value', js['shortUrl'])
       // } //else {
          //  alert( " An error has occurred: " + xhttp.statusText);
       // }
    // }
  }
xhttp.send();
var but = document.createElement("input");
but.setAttribute('type', 'button')
but.setAttribute('class', 'next action-button')
but.setAttribute('value', 'Copy')
but.setAttribute('onClick', "myFunction()")

function myFunction() {
  /* Get the text field */
  var copyText = document.getElementById("tagg");

  /* Select the text field */
  copyText.select();
  copyText.setSelectionRange(0, 99999); /* For mobile devices */

  /* Copy the text inside the text field */
  document.execCommand("copy");

  /* Alert the copied text */
  alert("Copied the text: " + copyText.value);
}


   var z = document.getElementById("r2");

  
  var xmlHttp = new XMLHttpRequest();


  if (x.style.display === "none") {
    x.style.display = "block";
  } else {
    x.style.display = "none";
  }

  if (y.style.display === "none") {
    y.style.display = "block";
  } else {
    y.style.display = "none";
  }
 var zo = document.getElementById("expa");
   if (zo.style.display === "none") {
    zo.style.display = "block";
  } else {
    zo.style.display = "none";
  }
  if (z.style.display === "none") {
    y.style.display = "block";
  } else {
    z.style.display = "none";
  }

  var element = document.getElementById("oi");
  element.appendChild(tag);
  element.appendChild(but);
  
}